<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<script>
		function changeCss(){
			var d1=document.getElementById("d1");
			//d1.setAttribute("style","font-size:69px;border:40px solid red;"));
			d1.style.fontSize="60px";
			d1.style.border="40px solid red";
			d1.style.display="none";
		}
		function changeCss2(){
			var d2=document.getElementById("d2");
			d2.className="f2";
		}
		</script>
		<style>
		 .f2{
			 border: 4px solid red;
			 text-align: center;
			 border-radius: 50%;
		 }
		</style>
	</head>
	<body>
		<div id="d1" >
			席组陈回家过年！
		</div>
		<div id="d2">
			孙楠楠认真在家自习！
		</div>
		<div>
			<button type="button" onclick="changeCss()">修改Css</button>
			<button type="button" onclick="changeCss2()">修改Css2</button>
		</div>
	</body>
</html>
